The invention relates to a timed chime apparatus for a clock, and, more particularly, to such an apparatus including electronic means for periodically generating a number of chime tones corresponding to the time of the clock.
A timed chime system utilizing a crystal controlled clock is disclosed in the published German patent applications Nos. 25-56-765 and 26-09-871 which are incorporated herein by reference. In the system of the cited German patent applications, an angular coder is connected to the hour spindle of a clock and the minute spindle of the clock carries a contact arm that moves over stationary contacts to define a minute chime sequence.
In operation, the contact arm of the minute spindle moves to a start chime position to initiate a gong sequence having a maximum of four strokes for the full hour. For this purpose, an electromotor is energized to move a cam shaft and an associated hammer to produce an audible gong for each quarter hour. For each movement of the minute cam shaft there is generated a corresponding electrical pulse and each pulse is counted by a reference circuit.
When the appropriate count of the electrical pulses for the minute gongs is reached, the reference circuit initiates the reading of the angular coder having a BCD code corresponding to the position of the hour hand of the clock. Thereafter, an electromotor is energized to move an hour cam shaft and to thereby produce a series of audible hour gong signals. For each hour gong signal, a corresponding electrical pulse is generated and applied to the reference circuit. The number of such hour gong pulses is compared to the BCD code number of the angular coder and, when the number of hour gong pulses is the same as the BCD code number, the gong activation circuitry is turned off.
The chime apparatus of the cited German patent applications has the disadvantage that it is mechanical in operation and, therefore, is subject to the problems of wear and mechanical failure that are associated with such devices. Furthermore, a great number of sliding contacts are used by the apparatus and these contacts do not generally operate satisfactorily at all times. Also, the design of the electronic circuitry for the system is complicated due to the division of system control between the quarter hour and full hour signals. In addition, the system does not use electronic tones because of technical problems relating to the application of power in electronic tone systems and to the electronic generation of proper tones.
Accordingly, it is an object of the invention to provide a relatively simple and power-efficient electronic system for generating timed audible tones to signal the time of a clock.
Another object of the invention is to provide a means for generating timed audible signals comprising a sequence of tones.
These and other objects of this invention will become apparent from a review of the detailed specification which follows and a consideration of the accompanying drawings in which like reference characters identify identical apparatus.